基于SIW圆极化赋形阵列的毫米波可重构切换波束天线研究

The MMW (Millimeter Wave) is an important direction for the development of high-rate and miniaturized communication systems in the future. Due to the high path loss of MMW，traditional omnidirectional antennas are difficult to maintain the distant communication with low power, and the switched beam based on multi-directional antennas is one of the effective solutions. However, in the traditional beam switching systems，pen beams have a greatly limited application for 3D coverage，and there is a 3dB gain gap between the adjacent beams. The SIW (Substrate Integrated Waveguide) has advantages of the microstrip line and waveguide. Based on the SIW，this project carries out the researches on the MMW switching beam antenna，which has advantages of the shaped beam，reconfigurable beam and circular polarization. The circularly polarized SIW antenna with wideband and wide beam width for shaped beam arrays will be studied. To achieve multi goals including the objective pattern, good circular polarization and low side lobe, a beamforming optimization algorithm combined by the genetic algorithm and HFSS simulation will be developed, and a shaped beam with a cosecant squared distribution will be obtained. The switching beam antenna based on a reconfigurable switch network will be studied, and a combined new beam will be achieved between adjacent beams to compensate the 3dB gain gap. The results of the project will increase the designs of SIW circularly polarized antennas and promote the development of MMW switching beam antennas.

毫米波是未来高速率小型化通信系统发展的重要方向。由于毫米波路径损耗大，传统的全向天线难以兼顾通信距离和低功率，而基于多个定向天线的切换波束是有效解决方法之一。然而，传统切换波束中的笔状波束应用于3D覆盖时受到很大的限制，而且切换波束之间存在3dB的增益衰落。由于基片集成波导（Substrate Integrated Waveguide, SIW）结合了微带线和波导的优点，本课题拟基于SIW研究结合了赋形、可重构、圆极化的毫米波切换波束天线：研究适用于赋形阵列的SIW宽带宽波束圆极化天线；研究遗传算法结合HFSS仿真并且兼顾方向图、圆极化特性和副瓣电平的多目标优化算法，以获得俯仰面余割平方分布的波束；研究基于可重构开关网络的切换波束天线，可以使任意相邻波束组合成新波束以补偿3dB增益衰落。本项研究将丰富SIW圆极化天线的技术方案，促进毫米波切换波束天线的发展。

随着毫米波通信系统地广泛应用，人们对作为重要部件的天线提出了更高的要求，包括圆极化、宽频带、高增益、平面化、易集成以及波束赋形、可重构等等。为此，本项目瞄准平面圆极化天线及阵列的应用需求，将结合了波导和微带线优点的基片集成波导（Substrate Integrated Waveguide, SIW）作为馈线，重点围绕上述需求开展相关的研究。具体研究内容可分为以下三个方面：（1）由SIW馈电的具有宽频带、较高增益、平面化、易集成等特点的圆极化天线单元及其组成的高增益阵列设计。所涉及的圆极化天线包括电磁偶极子天线、端射环形天线、交叉偶极子天线和平面双螺旋天线。（2）针对阵列天线波束赋形中智能优化算法精度不高，收敛速度不快等问题，在猫群算法的基础上，使其基本参数根据迭代次数及适应度函数值自适应改变，并且在搜寻模式中加入赌轮盘和精英选择相结合的策略，构成自适应猫群算法从而有效提高波束赋形的效率；其次，通过Matlab调用全波仿真软件HFSS，将考虑了阵元之间耦合的阵列波束赋形仿真结果导入Matlab波束赋形优化程序中作对比，从而提高波束赋形精度；最后，将上述算法应用于实际阵列的多目标波束赋形，取得了良好效果。（3）毫米波可重构开关网络的设计。基于现有毫米波开关芯片，设计了一分八的可重构开关网络，通过控制开关芯片可实现八单元环形阵列中任一天线的接收与发射，也可以实现相邻天线的组合接收与发射，从而获得双倍的可切换波束。研究成果可应用于对圆极化单元及阵列的整体性能要求较高的通信及雷达设备中，在军事和民用方面均有十分广阔的应用前景。项目基本完成了资助计划书中的研究目标，在项目资助下取得了丰富的研究成果，具体包括：发表论文共计14篇，其中SCI检索论文5篇，EI检索论文8篇，获得发明专利授权3项，申请受理1项。